Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit 9.6.16 -> satisfiable by phpunit/phpunit[9.6.16]. - phpunit/phpunit 9.6.16 requires ext-dom * -> it is missing from your system. Install or enable PHP's dom extension. Problem 2 - Root composer.json requires mediawiki/mediawiki-codesniffer 45.0.0 -> satisfiable by mediawiki/mediawiki-codesniffer[v45.0.0]. - mediawiki/mediawiki-codesniffer v45.0.0 requires squizlabs/php_codesniffer 3.10.3 -> satisfiable by squizlabs/php_codesniffer[3.10.3]. - squizlabs/php_codesniffer[3.0.0, ..., 3.11.2] require ext-simplexml * -> it is missing from your system. Install or enable PHP's simplexml extension. To enable extensions, verify that they are enabled in your .ini files: - /etc/php/8.4/cli/php.ini - /etc/php/8.4/cli/conf.d/10-opcache.ini - /etc/php/8.4/cli/conf.d/10-pdo.ini - /etc/php/8.4/cli/conf.d/20-apcu.ini - /etc/php/8.4/cli/conf.d/20-calendar.ini - /etc/php/8.4/cli/conf.d/20-ctype.ini - /etc/php/8.4/cli/conf.d/20-exif.ini - /etc/php/8.4/cli/conf.d/20-ffi.ini - /etc/php/8.4/cli/conf.d/20-fileinfo.ini - /etc/php/8.4/cli/conf.d/20-ftp.ini - /etc/php/8.4/cli/conf.d/20-gettext.ini - /etc/php/8.4/cli/conf.d/20-iconv.ini - /etc/php/8.4/cli/conf.d/20-phar.ini - /etc/php/8.4/cli/conf.d/20-posix.ini - /etc/php/8.4/cli/conf.d/20-readline.ini - /etc/php/8.4/cli/conf.d/20-shmop.ini - /etc/php/8.4/cli/conf.d/20-sockets.ini - /etc/php/8.4/cli/conf.d/20-sysvmsg.ini - /etc/php/8.4/cli/conf.d/20-sysvsem.ini - /etc/php/8.4/cli/conf.d/20-sysvshm.ini - /etc/php/8.4/cli/conf.d/20-tokenizer.ini You can also run `php --ini` in a terminal to see which files are used by PHP in CLI mode. Alternatively, you can run Composer with `--ignore-platform-req=ext-dom --ignore-platform-req=ext-simplexml` to temporarily ignore these required extensions.